The main disadvantage with sonourethrogram is lack of information regarding to posterior urethra pathologies. Retrograde urethrogram is better in understanding posterior urethral pathologies. This study helps to understand the advantages of sonourethrogram over retrograde urethrogram, helps to understand the level of utility of sonourethrogram in demonstrating urethral pathologies in comparision with retrograde urethrogram.

Type of study & period of study: This study was conducted in department of radiology in Kurnool medical college for four years, between 2015 to 2019. This study was basically a comparative study between sonourethrogram and retrograde urethrogram.

Inclusion criteria: Patients with symptoms pertaining to urethral pathologies were selected.

Exclusion criteria: Congenital urethral anomalies and patients with recent trauma were excluded from the study.

Patients with acute urethral infections were also excluded.

Patients with moderate to severe meatal stenosis are excluded.

A total of 60 patients were selected who came for retrograde urethrogram especially those with chronic infection history without any recent trauma or symptoms suggesting acute infection. All patients requested and took informed consent for sonourethrogram.

Study design: Philips, GE and Esoate machines were used to examine male urethra, using probes with frequency 3-12 MHz, after filling urethra with saline. Ascending technique was used in sonourethrogram.

Findings were divided into mucosal irregularities suggesting chronic urethritis, strictures either long segmented or short segmented, diverticulae, false passages, periurethral fibrosis, periurethral abscess and urethral calculus. Results were compared with the retrograde urethrogram.

Statistical analysis: Results were analyzed using Cohen kappa statistical measurements rather than simple percent calculations as it takes into account the possibility of agreement occurring by chance.

Out of 60 patients, 59 had strictures shown in retrograde urethrogram either in penile, bulbar [Fig 1,2,3 and 4] or membranous parts. Only one patient had membranous urethral stricture in retrograde urethrogram which was not shown in sonourethrogram. All other patients had shown strictures in sonourethrogram. One patient had penile urethral calculus [Fig 5] shown in both sonourethrogram and retrograde urethrogram. Out of 59 who had strictures, 30 were in penile region, 26 were in bulbar region, and in both penile and bulbar parts in 3 patients.

Out of 60 patients, 46 patients had irregular mucosa, 10 patients had false passages, 5 patients had abscess in periurethral region, 15 patients had diverticulae described in retrograde urethrogram [Table 3]. In sonourethrogram, only 08 patients shown false passages and periurethral fibrosis was shown in 25 patients. Periurethral fibrosis was not identified in retrograde urethrogram. Statistical evaluation is shown in Table 3.

Fig: 3 B

Fig: 3 C

Fig-3. A] retrograde urethrogram showing multiple strictures in penile and bulbar parts. Proximal penile urethra shows a filling defect posterior to stricture representing a calculus.

B] Sonourethrogram shows stricture in proximal penile urethra with periurethral fibrosis and a calculus proximal to stricture.

C] multiple areas of stenosis in penile urethra with periurethral fibrosis.

Fig: 4 A

Fig: 4 B

Further characterization of strictures in terms of length, periurethral pathologies like periurethral fibrosis, diverticula, abscesses, fistulas and false tracts can be performed with relatively greater sensitivity using the sonourethrography [2]. With sonourethrogram, it is difficult to evaluate posterior urethra owing to its inability to scan the urethra in a perpendicular fashion [3]. Ultrasonography can be used as an adjunct to determine the length and degree of spongiofibrosis, and can influence the operative approach [4].

Because sonographic measurements are often longer, new ultrasonic criteria proposed indicate resection and end-to-end anastomosis for adult bulbar stricture measuring up to 25 mm. Ability of sonourethrography to diagnose periurethral pathologies and length of stricture especially in bulbar urethra helps surgeon to plan proper surgical procedure [2]. Periurethral fibrosis is a critical determinant of appropriate therapy and ultimate prognosis [5]. Excessive fibrosis is said to be responsible for high recurrence rates [6].

Ultrasonography of the urethra was shown to directly influence the reconstructive operative approach for anterior urethroplasty in 45% of cases [1]. Gray scale imaging with doppler seems to be superior to radio urethrography for treatment planning. Sonoure-thrography and MR imaging have been proposed, distending the lumen with simple saline solution instead of iodinated contrast media. They are being used to study the urethral mucosa and the periurethral spongy tissue which can be involved in the urethral pathologies such as strictures, diverticula, trauma, and tumors [7].

Ascending ultrasound technique whereby a catheter was placed distally in a similar manner to contrast urethrography with a balloon inflated in the fossa navicularis and the urethra distended with either saline or, if a conventional urethrogram was also required, contrast medium. Ultrasound was performed using a high-frequency linear array transducer with direct skin contact along the ventral surface of the penis. Subscrotal and perineal views were obtained. There are a number of disadvantages, including the fact that it may not be possible to catheterise the distal urethra, particularly in patients with meatal stenosis or previous surgery. Also, the technique is necessarily invasive, and interpretation may be hampered by the presence of air bubbles, which may obscure pathology or even provide a false-positive study.

Sonourethrogram is easily available, cost effective technique that uses no radiation in the evaluation of male urethra. It is equally effective compared to retrograde urethrogram in the evaluation of male anterior urethral strictures. Periurethral pathologies like fibrosis are better evaluated with sonourethrogram rather than retrograde urethrogram. It is also important in the surgical planning and approach. However, posterior urethral pathologies are difficult to be visualized by sonourethrogram.

This study proves that sonourethrogram is more useful in obtaining information regarding periurethral pathologies like extent of fibrosis accurately than retrograde urethrogram, that helps in surgical planning.

The present study proves and reinforces that this investigation needed to be performed more often than it is now especially in preoperative stages so that length and extent of fibrosis can be estimated correctly that helps in surgical planning.

Acknowledgment: Author would like to extend his gratitude to Dr. Joji Reddy sir, who is professor and H.O.D of Department of Radiology, and to Dr. Suresh Balla, who is an Associate Professor in the same department for helping out to complete this study.